On Sept. 19, 2014, the five-day average of Antarctic sea ice extent exceeded 20 million square kilometers for the first time since 1979, according to the National Snow and Ice Data Center. The red line shows the average maximum extent from 1979-2014. (NASA's Scientific Visualization Studio/Cindy Starr)

Although the Amundsen Sea region is only a fraction of the whole West Antarctic Ice Sheet, the region contains enough ice to raise global sea levels by 4 feet (1.2 meters).

True colour satellite image of the Earth centred on the South Pole with cloud coverage, during winter solstice at 6 a.m GMT. This image in orthographic projection was compiled from data acquired by LANDSAT 5 & 7 satellites., Globe Centred On The South Pole, True Colour Satellite Image (Photo by Planet Observer/Universal Images Group via Getty Images)

This image obtained from NASA 15 May 2007 shows what a team of NASA and university scientists say 15 May 2007 is clear evidence that extensive areas of snow melted in west Antarctica (left) in January 2005 in response to warm temperatures. This was the first widespread Antarctic melting ever detected with NASA's QuikScat satellite and the most significant melt observed using satellites during the past three decades. Combined, the affected regions encompassed an area as big as California. The NASA statement described the findings as 'the most significant melt observed using satellites during the past three decades.' (Photo credit should read -/AFP/Getty Images)

GLACIER CALVING, ANTARCTICA - JANUARY 27, 2012: This is a satellite image of a glacier calving in Antarctica, collected on January 27, 2012. (Photo DigitalGlobe via Getty Images)

Earth. True colour satellite image of the Earth, centred on Antarctica. The South Pole is at centre. Antarctica is a frozen continent, permanently covered in snow and ice. Surrounding Antarctica are the waters of the Southern Ocean, mixing with the Atlantic Ocean (upper centre), the Pacific Ocean (lower left) and the Indian Ocean (centre right). Around the edge of the hemisphere is New Zealand (lower centre), Australia (lower right), and the southern parts of Africa (upper right, the island of Madagascar is also seen) and South America (upper left). The image used data from LANDSAT 5 & 7 satellites. Print size 42x42cm., Globe South Pole, True Colour Satellite Image (Photo by Planet Observer/Universal Images Group via Getty Images)